Alterations in cell surface proteins associated with oncogenic transformation will be studied using tissue culture cells. Individual molecules will be investigated using chemical and metabolic labeling methods. The functions of specific proteins in phenotypic properties of cells (adhesion, growth control, morphology, etc.) will be tested. Possible mechanisms for the alterations, such as the role of proteases will be investigated. Biosynthesis and processing will be studied using immunoprecipitation methods. Spatial organization at the cell surface will be investigated using crosslinking reagents and immunofluorescence microscopy. Interactions between surface molecules and between the surface and the cytoskeleton will be studied as well as changes in these interactions caused by transformation.